Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
2,049
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QGIS point sampling misses data on edge of raster (possible bug?)
It seems I may have discovered a shortcoming in the way QGIS handles raster sampling in points. Since yesterday evening (18/7), one small issue has begun to elude me (during my comeback geofictional ...
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Reprojecting to rotated orthographic projection in rasterio
I have some DEMs in a lunar polar stereographic projection (from LOLA). I would like to reproject them to a orthographic projection with a custom azimuth rotation using rasterio. I can pretty easily ...
- 101
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QGIS fill individual sink
I’m trying to determine the maximum extent of a pond when it is filled to its maximum capacity.
I think this is the same logic as the sink filling algorithms used for hydraulically correct dem’s - but ...
- 617
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Brightness Differences in DEM TIFF File
I created a DEM file with QGIS. File type TIFF. The files I use as sources are also TIFF. The file, which looks normal in QGIS, looks different when I look at it in other programs. When I open the DEM ...
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Why does my raster look different after clipping it by a mask layer using QGIS?
I have a Digital Elevation Model of Europe and I want to clip it to the extent of Germany. To do so, I am using Clip Raster by Mask Layer with the external frontier of Germany as the mask layer. ...
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WGS84 elevation from ALOS 30m DSM tif's using rasterio
I am new to GIS processing.
I am trying to compute WGS84 elevation for given latitude and longitude using the JAXA ALOS 30m DSM. I use rasterio and code from a minimal example I found that looks like ...
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I can't fill in the gaps in the DEM map [closed]
I downloaded the DEM files of the Balkan peninsula from the USGS website. I created a Balkan Peninsula DEM map larger than 3 GB from more than 130 DEM files, each of which is 25 MB. However, there is ...
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130 TIF DEM file (total size 3 GB) become 7.4 GB TIF file after merging. Why?
I combined (Merge) 130 DEM maps via QGIS, taking up 3 GB in total. However, the total size of the combined file was 7.4 GB. I'm new to QGIS. It's only been a few weeks. I don't understand why the file ...
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Merging DEM with different resolutions
I am going to merge two DEM raster files with different resolutions (5m and 12.5m). I would like to merge them in a way that they should keep their own resolution.
How can I do this in ArcGIS Pro?
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DEM < 10 Meters - Greece
I would like to know if there is any free or to buy option (site) from which I can buy/download a high resolution DEM for a small region in Greece. Except from USGS and OpenToography where the ...
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Combine DTM with hillshade in QGIS
I'm wondering if it is possible to combine a LiDAR generated DTM on a 1m Scale with a Hillshade DTM on a 0,25m Scale to improve the level of detail of the LiDAR DTM.
If possible how can this be done ...
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GSD or pixel size for volume
When I want to calculate the volume of a building polygon (in my case), do I use the GSD that I received in a WebODM report or the pixel size of the elevation raster? What is the difference between ...
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Issue generating DEM with Natural Neighbour in QGIS 3.6 on different computers
I am trying to create a DEM using the Natural Neighbour algorithm in QGIS 3.6 Noosa. On my personal computer, I can successfully generate the DEM despite encountering a warning (shown in the attached ...
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QGIS DEM to elevation Points, pixels not centred
I have a DEM which I'm trying to convert into a point layer in QGIS. I used the raster pixels to points tool, which seemed to work, except that the points are not in the centre of the DEM pixels. They ...
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QGIS: Set two raster to the same height
I have 2 DEM raster in QGIS. I want to merge them, but they have a difference in height of approx. 9m. This means that when I merge them, there is a kind of break-off edge at the transition. Can I ...
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